1/2 1/3 1/4~~~~~~~~~~~~~~~~~1/100,选10个数,相加等于1
问题描述:
1/2 1/3 1/4~~~~~~~~~~~~~~~~~1/100,选10个数,相加等于1
答
根据:
1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10=1-1/10
所以 :
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/10=1